feat: Release v0.10 - Modular Architecture & External Config

- Refactor codebase into src/ (preprocessing, translation, assembly)
- Add pipeline/ scripts for individual stages
- Externalize configuration to config/config.yaml
- Fix Cover Image preservation
- Update documentation and manuals

src/translation/manifest_manager.py

@@ -0,0 +1,74 @@
+from pathlib import Path
+from typing import List, Dict, Optional
+import json
+from src.common.data_model import ManifestEntry
+from src.common.utils import setup_logger
+
+logger = setup_logger("manifest_manager")
+
+class ManifestManager:
+    """
+    Manages the translation manifest (Source of Truth).
+    Handles persistence and state updates.
+    """
+    
+    def __init__(self, manifest_path: Path):
+        self.manifest_path = manifest_path
+        self.entries: List[ManifestEntry] = []
+        self._entries_map: Dict[str, ManifestEntry] = {}
+        
+    def load(self):
+        """Loads manifest from disk if it exists."""
+        if not self.manifest_path.exists():
+            logger.info(f"Manifest not found at {self.manifest_path}, starting empty.")
+            return
+
+        try:
+            with open(self.manifest_path, 'r', encoding='utf-8') as f:
+                data = json.load(f)
+                self.entries = [ManifestEntry.model_validate(item) for item in data]
+                self._rebuild_map()
+            logger.info(f"Loaded {len(self.entries)} entries from manifest.")
+        except Exception as e:
+            logger.error(f"Failed to load manifest: {e}")
+            raise
+
+    def save(self):
+        """Saves current state to disk."""
+        try:
+            # Pydantic v2: model_dump(mode='json') or just list dump
+            data = [entry.model_dump(mode='json') for entry in self.entries]
+            with open(self.manifest_path, 'w', encoding='utf-8') as f:
+                json.dump(data, f, indent=2, ensure_ascii=False)
+            logger.info(f"Saved {len(self.entries)} entries to manifest.")
+        except Exception as e:
+            logger.error(f"Failed to save manifest: {e}")
+            raise
+
+    def add_entries(self, new_entries: List[ManifestEntry]):
+        """
+        Adds new entries to the manifest.
+        If an entry with the same ID exists, it keeps the EXISTING one (to preserve translations).
+        """
+        count = 0
+        for entry in new_entries:
+            if entry.entry_id not in self._entries_map:
+                self.entries.append(entry)
+                self._entries_map[entry.entry_id] = entry
+                count += 1
+        
+        if count > 0:
+            logger.info(f"Added {count} new entries to manifest.")
+            
+    def update_translation(self, entry_id: str, translation: str):
+        """Updates translation for a specific entry."""
+        if entry_id in self._entries_map:
+            self._entries_map[entry_id].translated_text = translation
+        else:
+            logger.warning(f"Attempted to update translation for unknown ID: {entry_id}")
+
+    def get_entry(self, entry_id: str) -> Optional[ManifestEntry]:
+        return self._entries_map.get(entry_id)
+
+    def _rebuild_map(self):
+        self._entries_map = {e.entry_id: e for e in self.entries}